Numerous patents have been issued on examination and/or surgical gynecological instruments. Devices for retracting the vaginal cavity for gynecological procedures include medical or surgical instruments known variously as speculums, dilators and retractors.
The speculums may be held in place by gravity. Such speculums are known as the weighted speculums. The weighted speculums are well known in gynecology for depressing the posterior (lower) vaginal wall of patients during surgery or other gynecological procedures. However, weighted speculums move, slip and fall onto the floor or even onto the surgeon's feet. They are sometimes slip and fall, because they do not have any additional secure support in the vaginal cavity except the weighted speculum portion inserted into vagina (also known as a weighted speculum blade). The speculum blade is the only one element of the weighted speculum which holds the speculum on the posterior vaginal wall.
As a result, the gynecologist's (surgeon's) is not under control of the weighted speculum position inside vagina during procedure (surgery), considering the possible mobility of the weighted speculum inside vagina [the position of the weighted speculum inside vagina is not securely fixed (retained) during procedure (surgery)].
Also, the surgeon may not control the view required to perform any particular procedure considering the speculum's mobility inside vagina. Heavy weighted speculums come in standard manufactured sizes and sometimes do not fully meet the gynecologist's needs.
All of these factors may affect the quality of the gynecological procedure or surgery, increase procedure time, contribute to the surgeon's frustration, and increase the cost of the surgery or the procedure and the risk of complications.
Another common approach to provide additional and sufficient space for a vaginal surgery is simply to retract the left and right vaginal walls. The most used instruments for such purpose are the manual retractor devises. Generally, the manual retractor device is a two banded (e.g. hook-configured) retractors, each of which is manually (e.g. by the surgeon's assistant) engaged to the middle of the edges of the left and right walls of the patient's vagina and pulled in the opposite to each other direction as far as the left and right vaginal walls may be stretched.
Various improvements have been made to these retractors, making it unnecessary for assistants or nurses to hold them, and also making it possible to provide different degrees of opening with the same equipment.
There are known many medical speculum and retractor devices. For instance, U.S. Pat. No. 7,604,609 to Jervis describes the bendable, reusable medical instruments with improved fatigue life. Generally, it is a needle device which is manufactured from shape memory or pseudo-elastic materials, such as Nickel Titanium alloys. This device may be provided having an initial shape which a doctor may bend to a desired shape. The device may be easily returned to its initial shape after use by heating the device above a predetermined sterilization temperature. This cycle may be repeated during subsequent uses due to the reduced work hardening and enhanced fatigue properties of the Nickel Titanium device.
In accordance with the invention, medical instrument may be manufactured from materials, such as Nitinol alloys, having heat-activated shape memory and/or super-elastic properties with incomplete hysteretic, which provide improved fatigue life. As it is known from invention, the Nitinol alloys, which are exclusively or principally composed of nickel and titanium, exhibit metallurgical properties superior to conventional metals, such as stainless steel and aluminum, in this regard. Martensitic, binary Nitinol, for example, has a stress-strain characteristic which plateaus in a manner permitting unusually large deformations at essentially constant stress through a process of crystallographic twinning. Because of the nature of this twinning, the alloy has comparatively little work hardening which greatly enhances its fatigue properties. Super-elastic Nitinol that does not spontaneously complete its hysteretic cycle after deformation exhibits similar behavior which is due to the formation of stress-induced martensite.
These forms of Nitinol are appropriate for the purposes of making instruments which can be formed during repeated use without adverse effects. A bendable instrument in accordance with the invention may be provided having an initial orientation or shape, a doctor (surgeon) may bend the instrument to a desired shape for use during a procedure, and then the instrument may be returned to its initial shape after use.
For example, a bendable portion of an instrument may be made from a martensitic alloy, that is formed into its initial shape at an elevated temperature while the alloy is in its austenitic phase. During the course of a procedure while at substantially ambient temperatures, the bendable portion may formed into one or more desired shapes. After being used in a procedure, the instrument may be heat sterilized or otherwise heated, thereby automatically returning it to its initial shape such that the user is always presented with a standard shape when the instrument is supplied for subsequent use.
More specifically, the device comprises in general: a vein harvesting hook including a shaft and a working portion and a distal portion of the hook. The shaft includes a small bend and the working portion, which includes an arcuate portion that terminates in a distal tip. During use in a vein harvesting procedure, a surgeon has possibility to bend the hook, for example changing the angle of the bend, or repeatedly adjusting the radius of the arcuate portion to desired shapes suitable for the anatomy encountered during the procedure. After the procedure is completed, the hook may be bent back to its initial shape for reuse.
Also, the described instrument has a weighted speculum, which includes another distal portion and a weighted proximal portion, that are formed to have an initial shape, i.e. a predetermined angle between that another distal and proximal portions. The another distal portion has a contoured arm that is adapted to be inserted into the vaginal canal to facilitate observation and/or access during a gynecological procedure. The proximal portion includes a weight, typically integrally formed in the proximal portion, such that when that another distal portion is inserted into the vaginal canal, the weight pulls the posterior wall down to maintain an opening for accessing or observing the interior of the vagina.
This instrument is expensive, requires special thermal treatments for its adjustability. Another U.S. Pat. No. 6,120,438 to Rezvi describes a posterior vaginal retractor for vaginal surgery or procedure. This device includes a flat plate member, a support member connected to plate member, and an arm member vertically adjustably connected to support member, a speculum member (blade) connected to arm member. The support member includes a first pin member, an elongated slot for slidably receiving pin member therein when arm member is vertically adjustably connected to support member. The speculum member includes a second pin member, and wherein the arm member defines an opening for receiving pin member therein when speculum member is connected to arm member. Also, the support member includes first and second opposed guide elements positioned for slidably receiving arm member therebetween. The arm member includes a handle element for grasping by a user. Arm member further defines an angled portion between opening and slot for enhancing the downward range of movement of arm member and speculum member in relationship with respect to support member. Additionally device comprises a plate member which includes a first triangular plate portion, a second plate portion extending from first plate portion, and a third plate portion extending from first plate portion and in parallel, spaced-apart relationship with second plate portion. The support member is connected to and extends upwardly from the appropriate plate portions.
In operation the first plate portion is positioned under the female patient's buttocks when the patient is on the operating table with legs up. Speculum member is inserted into the patient's vagina, and the position of speculum member is vertically adjusted to a desired fixed position by vertically moving arm member so that speculum member will depress the posterior wall of the vagina to facilitate a vaginal procedure or surgery. Speculum member is connected to arm member by positioning second pin member through opening and by threading nut element onto pin member so that speculum member is fixedly attached to arm member. The first pin member is positioned through elongated slot by slidably positioning arm member between guide elements. The handle element is projected from second side surface and in a direction away from support.
This device does not provide a retraction of vagina in the horizontal direction.
The medical retractor device by U.S. Pat. No. 5,183,032 dilates a vagina in at least three directions. The device generally comprises a supporting box, a mechanism proper, the blades, an opening and closing device. A supporting box comprises two flanges. These flanges are kept apart by spacers. The mechanism proper consists of a sliding member, moving between two flanges. The mechanism also comprises levers and connecting rods. The levers are pivotally mounted between flanges. That portion of the levers which is external to the flanges is in the shape of a circular arc, centered on the articulation point. In this way, when the apparatus is being opened, there is no relative lateral movement between the levers and the flanges and any risk of tearing or pinching the surrounding tissue is thereby obviated.
The device also includes the speculum blades and crankshaft. The blades are fitted perpendicularly to the ends of levers and to the sliding member. The translation of the sliding member induces the rotation of the levers. The sliding member and the levers actuate the blades, which bring about the widening of the vaginal cavity. The crankshaft is pivotable in between flanges. The crank-handle of the crankshaft is engaged in a hole in one end of the sliding member. The rotation of the crankshaft drives the sliding member.
The mechanism properly comprises the levers and connecting rods or links. The levers and connecting rods are symmetrically related to the vertical plane. Some levers are pivotally mounted in between flanges.
The grooved cam or driving means pivots about a shaft, which is positioned by bearings in between flanges and directly linked to a knurled handle control system. The anti-clockwise rotation of the cam drives the end of the connecting rods and thereby brings about the lateral movement of the connecting rods. This movement in turn drives the levers, which carry the blades. A sliding member, guided through a pivotally mounted shaft, connected at its lower end to the opening and closing device by a handle. The rotation of the cam directly induces the opening or closing of the sliding member.
This device is very complex and may require some degree of the surgeon's mechanical skills.
The U.S. Pat. No. 6,024,697 discloses a multi-bladed speculum for dilating a body cavity. This speculum includes the blades, the supporting arms, the connections between the supporting arms, the connections between the supporting arms and the blades, the illumination system, and the handles. Each blade is an elongated piece of material, preferably made of a clear hard plastic, with a slight curvature perpendicular to the long axis of the blade and concave to the cavity created by the speculum. The distal end of the blade has a slight curvature parallel to the long axis curved away from the cavity created by the speculum. The proximal end of the blade (the face) is bent in direction to the outside of the speculum. The preferred embodiment has three blades: a top blade, a left blade, and a right blade. The face of each blade consists of two surfaces, an anterior and a posterior face connected to each other at the point where the blade has finished bending to the outside of the speculum. The supporting arms are connected to the anterior and posterior faces in the space between the faces. The device has six supporting members—a left upper arm support, a left lower arm support, a left leg support, a right leg support, a right lower arm support, and a right upper arm support. The left upper arm support is connected to the left lower arm support by a bolt that allows these two supports to pivot about each other, creating a left elbow joint. The portion of the left lower arm support that is proximal to the left elbow joint, and that faces the inside of the speculum. The left upper arm support has a pawl made of a more flexible plastic material that is attached at one end to the left upper arm support. The left leg support is connected to the right leg support by a bolt that allows these two supports to pivot about each other, creating a hinge joint of the left and right leg supports. The portion of the left leg support that is proximal to this hinge joint, and that faces the inside of the speculum. The right leg support also made of a more flexible plastic material that is attached at one end to the right leg support.
Also, the device comprises a left ball-and-socket joint (the “ball” is a ball portion of the left leg support. The socket is formed from a cutaway section of the anterior face of the left blade just anterior and inferior to the ball portion of the left leg support as well as a depression in the posterior face of the left blade just posterior to the ball portion of the left leg support. The left leg support is pivotable) and a right ball-and-socket joint (the “ball” is a ball portion of the right leg support. The socket is formed from a cutaway section of the anterior face of the right blade just anterior and inferior to the ball portion of the right leg support as well as a depression in the posterior face of the right blade just posterior to the ball portion of the right leg support. The right leg support is pivotable too, and this not only allows the ball portion (and thus the right leg support itself) to rotate medially and laterally in the plane between the anterior and posterior faces, but also allows the ball portion of the right leg support to rotate anteriorly).
As it is described in this patent, the speculum has to be inserted as far as it can go, taking care to make sure that, for example, the dilated cervix is located inside the cavity formed by the speculum.
The disadvantage inherent in this retractor is that the device carrying the retractor blades and the parts which serve to support this device inevitably restrict the visibility of and access to the area requiring surgery. Inadequate exposure is a hindrance to the operator and can be particularly dangerous in micro-surgery, where, the surgeon's visibility being limited since he/she must manipulate without visual information in the zone where he moves his hands. It is of extreme importance that the area situated outside the opening should be completely unimpeded.
Additionally, this device is also very complex and may require some degree of the surgeon's mechanical skills.
There many other configurations of the vaginal retractors. For example, the U.S. Pat. No. 6,342,036 describes the self-retaining vaginal retractor. The retractor generally includes a base plate or frame having an inverted, generally U-shape form. The base plate mounts a top vagina retracting blade and a pair of cooperating side vagina retracting blades. The base plate is comprised of a horizontal upper member and a pair of spaced apart, parallel side legs extending perpendicularly downward from the upper member. A horizontal slot is defined through the upper member. A set of snap fasteners are mounted to the back of the upper member near the top of the base. Each of the base legs defines a vertical slot. The top vagina retracting blade and the side vagina retracting blades are secured to the base plate. The top retracting blade is connected to the upper member; and the side retracting blades are connected to the base legs 35. The integral retracting blades each of which has a curved tongue portions and appropriate handle portions. The handle portions define longitudinal slots to receive an adjustably tensionable fastener extending through the appropriate slots of the upper member and legs of the base plate. The tensionable fasteners each of which takes the form of a carriage bolt or similar screw extending through and indexing with a slots of the base plate and a wing nut used to secure the vagina retracting blade in place. The wing nuts are readily adjustable to allow the position of the retracting blades to be adjusted during and following initial deployment of the retractor. Also, device comprises a bag secured to the snap fasteners on the back of the upper member.
This device has a hard frame which limits the movements and positions of the surgeon's hands during gynecological procedure.
Thus, the known devices have some deficiencies, i.e. they are expensive and complex or do not provide an unobstructed access to and reasonably acceptable visibility of the inside vaginal area under gynecological procedure or surgery.
While the mentioned above prior art fulfill their respective, particular objectives and requirements, the mentioned prior art inventions do not disclose, teach and/or suggest the non-complex and non-expensive self-retaining vaginal retractor with a weighted speculum providing non-obstructed good visibility of the dilated body cavity and specifically of the vagina.
Those skilled in the art will readily observe that numerous modifications and advantages of the improved self-retaining vaginal retractor with a weighted speculum may be made while retaining the teachings of the invention.
Thus, the known prior art do not provide the efficient, not expensive, non-complex and convenient device for dilation of the patient vagina according to the present invention substantially departs from the devices of the prior art.